The present application relates generally to a chopper assembly for a combine. The present application relates more specifically to an apparatus for re-setting chopper elements of a counter knife bank in a chopper assembly to an operating position after striking a foreign object in the operating position.
Harvesting equipment, such as agricultural combines, can use chopper assemblies, such as integral chopper assemblies or hood mounted chopper assemblies or systems to transport material away from the threshing system and to also treat the material, e.g., by further cutting the material, as it is being transported away from the threshing system. A rotary chopper element or portion of the integral chopper system can be operated at or near 3,000 revolutions per minute (RPM) to transport the material from the threshing system to a spreading system. When operated at 3,000 RPM, the material is transported with the shortest mean length of cut to permit modern minimum tillage applications. In a less common embodiment, the integral chopper system can be operated at a speed of about 800 RPM to more gently transport the material from the threshing system to a spreading system and with considerably less chopping activity. When operated at 800 RPM, the material can be transported to the spreading system with the longest length and least amount of damage.
Integral chopper systems can have a residue chopper assembly that has a rotary chopper component or element disposed laterally within a housing extending generally horizontally across the flow path of the crop residue through the housing, as well as a counter knife assembly extending generally parallel to and spaced from the rotary chopper element. The counter knife assembly has included a chopper grate assembly spaced below and extending generally parallel to the rotary chopper element and a knife mounting assembly positioned generally beneath the chopper grate assembly.
Often, the counter knife assembly can have an adjustment mechanism that is operable to vary the spacing between a grate portion of the chopper grate assembly and the knife mounting assembly, as well as the degree of projection of the blade elements of the knife mounting assembly through the slots of the grate portion. The adjustment mechanism can be operated to move the knife mounting assembly between a fully engaged or inserted position with the blade elements of the knife mounting assembly extending through the slots towards the rotary chopper element and a fully retracted position in which the blade elements are fully withdrawn or retracted from the slots. In addition, the adjustment mechanism can move the blade elements to various positions between a fully engaged position and a fully retracted position.
When the knife mounting assembly is in an engaged position, either fully or partially, the crop residue can be chopped into smaller pieces by the cooperative actions of the knife blades or elements of the knife mounting assembly and the knife blades or paddles on the rotating rotary chopper element as the crop residue is moved and propelled rearward. The knife mounting assembly is usually positioned into an engaged position, either fully or partially, when the rotary chopper element is operated at or near 3,000 RPM and is usually positioned in a fully retracted position when the rotary chopper element is operated at 800 RPM to avoid excessive power requirements for the combine.
To avoid breakage of knives due to striking foreign objects ingested during harvesting, counter knife elements may be configured to deflect or break-away from respective operating positions to a non-working position. However, such configurations may require manual re-setting of the knife elements, which is undesirable.
In response, U.S. Pat. No. 5,928,080 utilizes a spring that permits cutting knives to be returned to an operating position upon being subjected to a foreign object, causing temporary angular deflection of the knives. However, such a spring could permit the knives to be angularly deflected to non-working position in response to an increase in working load. That is, the knives could be inadvertently moved to the non-working position during normal harvesting operating loads.
Therefore, what is needed is an apparatus usable with standard reversible, dual edged knives that requires an elevated amount of force greater than that associated with normal harvesting operations to angularly deflect the knives from an operating position, and then returning the knives to the operating position when the force is reduced.